The present invention relates to a craft which can be transported behind a vehicle by means of wheels which can be retracted when the craft is in the water.
Transportable crafts are increasingly widespread. Their users place them on trailers in order to transport them from their storage area to the water and back again. Said trailers feature relatively complex devices for handling the boat on the slip which is an inclined plane in the majority of ports.
There is a very large number of trailer types with a variety of more or less complicated handling devices. Almost all of these devices feature a winch and rollers to slide the boat into the water or to raise it onto the trailer. Some trailers feature an articulated chassis. Others are provided with a second trailer on top of the first, this second trailer being designed to enter the water, at which point the boat is completely released.
These various devices present numerous inconveniences, among which the complexity of handling, the mechanical complexity and all of failure risks it implies, the relatively long handling time which blocks the slip at the expense of other users, the high cost of a trailer in addition to the cost of the boat, and the size of a trailer which is difficult and costly to park near the port, in addition to the vehicle that pulls it.
In order to solve these inconveniences, boats have been designed with retractable wheels in the hull, as in the case of the craft described in FR-A-2.568.215. Each wheel is actuated by a specific lifting means which consists mainly of a lever arm, the end of which is directly secured to the axle of the wheel and the other end of which can be actuated directly and held in place by a locking means in either the retracted position or the running position.
In the craft described in FR-A-2.568.215, the housing in which the wheel is located is closed by a trap door to prevent water from entering the housing which would be considered a handicap when underway. The trap door is held in closed position by an elastic strap and is pushed back into open position when the wheel is out of its housing. Unfortunately, it turns out that this trap door presents a number of major disadvantages. When under way, the speed of the boat creates a suction force on the trap door which compensates the force of the elastic strap and causes the trap door to open, thus allowing water to penetrate into the housing. To solve this problem, it would obviously be possible to increase the tension of the return means, in this case the elastic strap. In this case, however, the significant tension force required to preclude the trap door from opening when under way, prevents it from being pushed open by the wheel when the craft is put in running position.
Another drawback of the trap door used in FR-A-2.568.215 is that the elastic strap is permanently stretched to its maximum when the craft is parked with the wheels extended, which eventually causes it to loose its efficiency.
Finally, when the craft is in running position, the trap door is in low position and thus very close to the ground, running the risk of impacts caused by bumps and other protruding elements on the running surface.
This is why the object of the invention is to provide a craft transportable by road, whose wheel housing trap door is integral with the wheel retraction mechanism and no longer subjected to an elastic return means.
The invention relates therefore to a craft transportable by road by being hitched at the rear of a vehicle, comprising two wheels capable of being extended from their housing into running position through an opening in the housing, each wheel being coupled by a shaft to one first end of a lever arm, the assembly being articulated on a shaft integral with the hull, and the second end of the lever arm being coupled by a shaft to a shock absorber fixed to a first support for maintaining the wheels in extended position. When the wheels are retracted in their housing, a trap door integral with the lever arm is urged to come to stop on a boss to close the housing opening after the shock absorber has been released and fixed on a second support integral with the lever arm and after the lever has been fixed to a third support integral with the hull, so as to close the opening completely, thereby preventing water from penetrating into the housing where the wheel is located.